Green plasticizers derived from epoxidized soybean oil for poly (vinyl chloride): Continuous synthesis and evaluation in PVC films

In this paper, the epoxidation process and the ring-opening reaction were integrated to develop an efficient bio-based plasticizer in a continuous flow mode. Four novel plasticizers based on epoxidized soybean oil (ESO) were prepared through integration of epoxidation catalyzed by α-Al₂O₃·H₂O and ring-opening reaction with H₂SO₄ as a catalyst. α-Al₂O₃·H₂O with different D₅₀ values was applied in the epoxidation reaction to investigate the role of particle size in the catalytic efficiency. Reasonable combination and arrangement of micromixers and flow reactors promoted the epoxidation reaction. Modified micro-flow system consisting of two micro-mixers and fixed bed flow reactors was applied in the epoxidation process, yielding ESO with an oxirane value of 6.1. Four as-prepared plasticizers were compared comprehensively based on mechanical property. Introduction of different bonds into the skeleton of ESO resulted in different mechanical performance.